JP2003340176A - Working method of cutter and its working device and inner blade for electric razor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain a burr of an edge, to omit deburring work, to reduce manufacturing cost, to lengthen a service life of a working tool, and to improve a working quality. <P>SOLUTION: In work of an edge of a cutter 1, grinding work is performed after making a work object surface 1a of at least the cutter 1 fragile previously or simultaneously with a grinding process. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of processing a cutting tool, a processing apparatus therefor, and an inner blade for an electric shaver.

[0002]

2. Description of the Related Art Conventionally, in the cutting edge cutting of a cutting tool, the cutting edge cutting (blading) is generally carried out by grinding, but when grinding the work surface of the cutting tool,
Accompanied by plastic deformation corresponding to the depth of cut. Therefore, when sharpening the cutting edge, there is a problem that a work-affected layer such as a burr is likely to occur. Further, since the cutting resistance against the processing tool increases during processing, power consumption during processing increases, the life of the processing tool is shortened, and deburring work is required in a post process.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the above-mentioned conventional example, and the purpose thereof is to suppress burr on the cutting edge and to omit the deburring work. Along with the provision of a method for processing a blade that can reduce the manufacturing cost, extend the life of the processing tool, and improve the processing quality, another object is to enable mass production in batches, and The purpose of the present invention is to provide a machining device for knives that can suppress the occurrence of burrs during grinding and can reduce the number of deburring steps that are performed later. It is to provide an inner blade for an electric shaver that is costly.

[0004]

[Means for Solving the Problems] In order to solve the above-mentioned problems, a method of processing a cutting tool according to the present invention is such that, in cutting the cutting edge of the cutting tool 1, at least the work surface 1a of the cutting tool 1 is embrittled before or at the same time as the grinding step. It is characterized in that the grinding process is performed after the cutting is performed. By configuring in this way, by embrittlement of the cutting tool 1, a work-affected layer such as plastic deformation at the time of working can be made as small as possible, and the cutting edge due to the plastic deformation can be minimized. 1b burr generation can be suppressed, deburring work is unnecessary, and
The life of the processing tool 2 can be extended.

Further, it is preferable that one side of the cutting tool 1 is the work surface 1a and the rib 3 having a convex cross-section is provided on the back side. In this case, the cutting edge can be formed by only one side grinding without double-side grinding like a safety razor. It is possible to sharpen 1b.

Further, it is preferable to subject the blade 1 to embrittlement processing in real time and perform grinding. In this case, an embrittlement atmosphere is created in the blade 1 in real time, and the atmosphere state is always maintained during processing. Atmospheric fluctuations are suppressed and the processing quality is improved.

Further, it is preferable that the cutting tool 1 is subjected to embrittlement treatment in advance and then subjected to the grinding work. In this case, the embrittlement treatment and the grinding work can be carried out separately.

Further, it is preferable that the cutting tool 1 is subjected to embrittlement treatment in a low temperature atmosphere and then ground, and in this case, it is possible to carry out processing by utilizing the property that ductility at room temperature gradually decreases. . That is, since the brittleness ratio increases as the temperature decreases, it is possible to suppress the occurrence of burrs on the cutting edge 1b due to the reduction in plastic deformation, and also reduce the energy during processing, so that the cutting resistance decreases and the life of the processing tool 2 also increases. Extend. Further, since the temperature is low, thermal effects such as thermal deformation and seizure can be suppressed as much as possible, and the life of the working tool 2 can be extended.

Further, it is preferable to cool the cutting tool 1 to a low temperature atmosphere and perform the grinding process. In this case, by cooling the cutting tool 1 itself, the work surface 1a can be made to be in a brittle state with high reliability. .

Further, it is preferable that the cutting tool 1 is frozen and then ground. In this case, the freezing of the cutting tool 1 causes not only a low-temperature embrittlement action but also surrounding ice to serve as a jig and the cutting edge 1b during grinding. It becomes a resistance against the occurrence of burrs.

Further, it is preferable to predict the size of the blade at room temperature and set the amount of processing under a low temperature atmosphere to be larger than the amount of processing at room temperature. In this case, a dimensional error due to thermal expansion and contraction will occur. It becomes possible to reduce as much as possible.

Further, it is preferable to cool the work surface 1a of the blade 1 which is in contact with the work tool 2 to a low temperature atmosphere and perform the grinding process. In this case, the work surface 1a of the blade 1 which is in contact with the work tool 2 is locally applied. By cooling, it is possible to perform the grinding process while surely making the work surface 1a brittle while simplifying the apparatus.

Further, it is preferable to cool the working tool 2 to a low temperature atmosphere and perform the grinding work. In this case, the embrittlement treatment can be performed without raising the temperature of the work surface 1a of the cutting tool 1 in contact with the working tool 2.

Further, it is preferable to cool the entire cutting tool 1 and the working tool 2 to a low temperature atmosphere and perform the grinding process. In this case, it becomes easy to control and maintain the entire cutting tool 1 and the working tool 2 in the same low temperature atmosphere, and to control the temperature. It becomes easier to peel.

Further, it is preferable to use the gas 6 as the cooling medium. In this case, handling and supply of the cooling medium become easy respectively.

Further, it is preferable to use the liquid 7 as the cooling medium, and in this case, the cooling efficiency is much higher than that in the case of the gas 6.

Further, it is preferable to circulate and reuse the cooling medium repeatedly. In this case, the cooling medium can be circulated and reused without waste, which is economical and causes less environmental problems.

It is preferable that the cutting tool 1 is made of a body-centered cubic crystal material. In this case, when the cutting tool 1 is cooled to a low temperature atmosphere to perform grinding, the body-centered cubic crystal material is sharply cut at a predetermined temperature. Has the property of increasing the brittleness ratio, it is possible to suppress the occurrence of burrs due to the effect of low temperature embrittlement, and the effect of extending the life of the working tool 2 is further enhanced.

It is preferable that the blade 1 is made of martensitic stainless steel. In this case, when the blade 1 is cooled to a low temperature atmosphere and is ground, the martensitic stainless steel has durability against rust and corrosion. Since it is expensive, it is convenient as a material for the blade 1, and since it has magnetism, it can be fixed by magnetic attraction.

It is preferable that the jig 1 be supported from the back side by the jig 5 during the grinding for grinding. In this case,
By supporting the cutting edge 1b having a sharp shape from the back side, it is possible to prevent elastic deformation, cracking or chipping due to the pressing force of the processing tool 2, and also prevent burr growth.

Further, the jig 5 is preferably ice 4, and in this case, the blade 1 can be cooled by the ice 4 to promote embrittlement, and the vicinity of the cutting edge 1b can be covered with the ice 4 to be supported. By processing such that the blade 1 and the ice 4 are cut at the same time as the blade 1, it is possible to suppress lateral growth of burrs that are likely to occur on the blade edge 1b.

Further, it is preferable that the jig 5 is made of wax. In this case, if the blade 8 is covered with the wax 8 up to the vicinity of the cutting edge 1b so as to be supported and the wax 8 is scraped at the same time as the blade 1, the cutting edge 1b can be removed. It is possible to suppress the lateral growth of burrs, which is likely to occur at the same time. Further, the wax 8 is easily fixed to the blade 1, and can be easily removed by heating even after the processing is completed.

Further, it is preferable that the jig 5 is made of metal. In this case, the jig 5 made of metal has a high supporting rigidity against a pressing force and can enhance the deformation suppressing effect against elastic deformation and plastic deformation.

Further, it is preferable that the work surface 1a of the cutting tool 1 is projected above the jig upper surface 5b in a stepped manner, and grinding is performed so that the jig upper surface 5b becomes a finished surface. In this case, The work surface 1a protruding above the jig 5 is brittlely fractured by the stress concentration due to the notch effect due to the step with the jig 5 and can be removed at one time.
The blade 1 part supported by is not affected by the destruction and only the unnecessary part can be removed.

Further, it is preferable that the cutting tool 1 is embrittled in a hydrogen atmosphere H and then subjected to grinding. In this case, by setting the cutting tool 1 in the hydrogen atmosphere H, the property of being ductile in the atmosphere gradually decreases. That is, processing can be performed by utilizing the property of hydrogen embrittlement.

Further, it is preferable to subject the blade 1 to an embrittlement treatment by quenching. In this case, by subjecting the blade 1 to a quenching treatment in advance to harden the surface thereof, the surface layer 1c having a ductile property has brittleness. As a result, the surface layer 1c has a faster cooling rate than the inside, the surface layer 1c has the highest hardness, and surface embrittlement occurs.

Further, it is preferable that the blade 1 is embrittled by laser hardening, and in this case, the surface 1 to be processed of the blade 1 is previously processed.
By irradiating the periphery of a with a laser to locally heat it, it is possible to perform heat treatment only on a local portion that requires embrittlement, and it is possible to reduce the deterioration layer due to dimensional changes such as warpage and deformation and thermal effects as much as possible.

Further, it is preferable to subject the blade 1 to embrittlement treatment by nitriding. In this case, the surface of the blade 1 is embrittled by nitriding in advance, so that plastic deformation due to a pressing force during processing can be suppressed, and chipping and The spread of damage such as chipping can be suppressed.

Further, it is preferable to subject the blade 1 to embrittlement treatment by spraying particles, and in this case, by spraying particles on the surface of the blade 1 in advance, the surface of the blade 1 is locally deformed to be embrittled simultaneously with work hardening. It is possible to suppress plastic deformation due to pressing force during processing.

Further, it is preferable to apply embrittlement treatment by adding a dissimilar material to the surface of the blade 1 in a film form. In this case, it is possible to suppress the spread of damage such as chipping or chipping during processing, and at the same time, the surface The presence of compressive residual stress improves fatigue strength and prolongs product life.

In addition, the processing apparatus for a cutting tool according to the present invention comprises means for making at least the work surface 1a of the cutting tool 1 brittle, a space 9 for creating a brittle atmosphere around the cutting tool 1, and the brittle cutting tool 1 And a working tool 2 for grinding, and is capable of performing grinding by embrittlement at least the work surface 1a of the blade 1, and by configuring in this way, It becomes possible to perform grinding processing in a brittle atmosphere in real time. Further, by storing a plurality of blades 1 in the space 9, it is possible to mass-produce in batches. Further, by making the work surface 1a of the blades 1 brittle and performing grinding, it is possible to suppress the occurrence of burrs during grinding. It is possible to reduce the subsequent deburring process.

The inner blade for an electric razor according to the present invention is
The blade 1 is an inner blade 12 that is in sliding contact with the inner surface of an outer blade 11 having a blade hole, and at least an inner blade edge 12b that is a sliding contact portion with the outer blade 11 is embrittled and ground. With such a configuration, a high-quality inner blade 12 that does not generate burrs on the cutting edge 1b during grinding, improves the sharpness of the cutting edge 1b, and has a good shaving taste for a beard is provided. In addition to being obtained, the burr removing step which has been necessary so far is not necessary, and the cost can be reduced.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the embodiments shown in the accompanying drawings.

FIG. 1 shows an example of a case of grinding a work surface 1a of a tool 1 (workpiece) that has been embrittled in advance (or simultaneously), and FIGS. As an example, the inner blade 12 for a reciprocating electric shaver is shown. In FIG. 2 and FIG. 3, the inner blade 12 has a structure in which a plurality of inner blade pieces 12a each having a semi-circular schematic shape are arranged so as to follow the outer blade, and the inner blade 12 is arranged on the base portion 13 communicating with the reciprocating drive source. It is installed. The inner blade 12a is roughly classified into a semi-disc type shown in FIG. 2 and a thin-walled annular type shown in FIG. In any case, as shown in FIG. 4, the cross section of the inner blade piece 12a has a flat inner blade edge 12b on one side, a sharp edge 1b at one side corner, and a rib 3 having a convex cross section on the back side. It has a complicated cross-sectional shape that is projected. Here, the reason why the rib 3 is provided on the back side is that there is a sensual effect of resonance amplifying the sound when the shaving is performed and giving a feeling of shaving. Generally, in a flat plate-shaped tool such as a knife, a kitchen knife, and a safety razor, there are many methods for edging the cutting edge while suppressing burrs by grinding both sides, but in the cutting edge shape as shown in FIG. It is difficult to use the processing tool 2 such as the grindstone 2a on the side of the wedge-shaped rake face 14, and the blade is attached by grinding only one side. In this case, during processing, burrs are generated in the vicinity of the work surface 1a of the cutting tool 1 due to plastic deformation according to the load.

Here, in the processing of the cutting edge of a metal material, the edging (blading) of the cutting edge 1b is generally performed by grinding. Generally, in pressure cutting such as cutting, grinding, and abrasive grains, the grindstone 2a is literally forcibly loaded onto the blade 1 to perform removal processing. Therefore,
At the time of processing, plastic deformation according to the load accompanies the surface 1a to be processed of the blade 1. For example, according to the literature (Taniguchi Norio: Fundamentals and Applications of Nanotechnology, Industrial Research Society, 1988), the ratio (c / a) of the spread c of plastic deformation to the indentation a given to the material surface is determined by the elastoplastic theory. There is a correlation with the ratio of the elastic modulus E to the hardness Hv of the material (E / Hv).
If (c / a) is replaced with the relationship between the amount of cutting of the grindstone 2a with respect to the cutting tool 1 and the amount of plastic deformation during processing, the behavior of plastic deformation accompanying processing can be explained. In the case of machining a cutting tool, if plastic deformation occurs in the cutting edge 1b, it becomes burr as it is and the finishing quality after grinding is poor, and it is necessary to remove the burr in a later step.

According to the present invention, at least the work surface 1a of the blade 1 is embrittled before or at the same time as the grinding step. By making the blade 1 brittle, a work-affected layer such as plastic deformation during working can be minimized and burrs can be suppressed. Examples of means for material embrittlement include low temperature embrittlement, hydrogen embrittlement, quench embrittlement, nitriding embrittlement, particle jet embrittlement, and application of a brittle film. These means are aimed at suppressing the occurrence of burrs on the cutting edge 1b due to plastic deformation by any means. Further, suppressing the plastic deformation on the work surface 1a means that the energy consumed for the plastic deformation can be reduced, and the cutting resistance to the grindstone 2a is reduced, so that the power consumption during the machining can be reduced and the life of the grindstone 2a can be extended. At the same time, the deburring work in the subsequent process becomes unnecessary.

Further, in the example shown in FIG. 4, a rib 3 having a convex cross section is provided on the back side of the cutting tool 1 so that the surface 1a to be processed of the cutting tool 1 is formed.
The surface to be processed 1 is made brittle before or at the same time as the grinding process.
Only a is ground into a planar shape, whereby the cutting edge 1b having an acute angle can be formed at the corner of the surface 1a to be processed by only one-side grinding. Moreover, in the case where the blade cross-sectional shape is a complicated shape having the convex rib 3 on the back side (when it is not a smooth plate-shaped tool), the work surface 1a of the tool 1 is embrittled during processing as described above. In addition to the effect that the work-affected layer such as plastic deformation during processing can be made as small as possible and the occurrence of burrs can be suppressed, the cutting edge 1b can be sharpened by one-side grinding without double-side grinding like a safety razor. Becomes

Another example of the present invention will be described below. First, FIG. 5 to FIG. 7 show an example of a case where the surface to be processed 1a is embrittled in real time for grinding. FIG. 5 shows a flowchart of this embodiment. After setting the starting point and the end point of the grindstone 2a and setting the embrittlement atmosphere target, the grindstone 2a is moved to the starting point and grinding is performed while maintaining the embrittlement atmosphere. This makes it possible to perform a desired amount of embrittlement processing while simultaneously performing real-time detection so that the periphery of the cutting tool 1 is in an embrittlement atmosphere, and at the same time perform grinding. Note that, for example, if the atmosphere is low temperature embrittlement, the temperature is targeted, and the coolant is cooled to the embrittlement temperature range of the blade 1, and grinding is performed at that temperature. For hydrogen embrittlement described later, the hydrogen concentration is targeted. Further, in order to perform the embrittlement treatment and the grinding process in real time, as shown in FIG. 6, the cooling medium 6a which becomes the embrittlement atmosphere is jetted from the nozzle 15 toward the work surface 1a, or as shown in FIG. Alternatively, a method in which the blade 1 and the grindstone 2a are stored in a closed container or a chamber and the cooling medium 6a which becomes an embrittlement atmosphere is enclosed together with the chamber can be considered. As a result, an embrittlement atmosphere can be created around the surface to be machined 1a in real time, and the atmosphere state is always maintained during processing. Therefore, the atmosphere variation due to processing is suppressed and the processing quality is improved.

FIG. 8 and FIG. 9 show an example of a case where the surface 1a to be processed is embrittled in advance and then ground.
FIG. 8 shows a flowchart in the case where a time difference is provided between the embrittlement processing step and the grinding step. In this method, FIG.
As shown in FIG. 9, after the embrittlement process is performed by injecting the cooling medium 6a that becomes an embrittlement atmosphere from the nozzle 15 toward the surface 1a to be processed, as shown in FIG. 9B, the grinding process by the grindstone 2a is performed. Give. The means for maintaining the brittleness of the cutting tool 1 may be a material-modifying means such as quenching, nitriding, or addition of a different material, which will be described later. According to this method, the conventional apparatus can be used because the embrittlement processing and the grinding processing can be performed separately, and the embrittlement processing and the grinding processing can be performed separately, which simplifies the apparatus. Therefore, the manufacturing cost can be reduced.

FIG. 10 shows low temperature embrittlement as an example of material embrittlement. The present embodiment is a method in which at least the surface 1a to be processed of the blade 1 is made into a low temperature atmosphere R to make it brittle and perform grinding. Generally, when a metal material is ground at room temperature, it is plastically deformed according to the depth of cut. Therefore, when the cutting edge 1b is sharpened, a work-affected layer such as a burr is likely to occur. Therefore, as shown in FIG. 10, the surface 1a to be processed is placed in a low temperature atmosphere R to perform processing by utilizing the property that the ductility at room temperature gradually deteriorates. Note that the ratio of brittle fracture surface in the impact test and the relationship between the energy and temperature leading to breakage increase the brittleness ratio and decrease the energy as the temperature decreases. This is because when the temperature is lowered, the absorbed energy at the time of impact is lowered and it is not spent for plastic deformation, leading to brittle fracture. According to this method, it is possible to suppress the occurrence of burrs on the cutting edge 1b due to the reduction of plastic deformation and also reduce the energy during processing, so that the cutting resistance is reduced and the life of the grindstone 2a can be extended. Further, since the temperature is low, the thermal influence such as the conventional thermal deformation and seizure can be suppressed as much as possible.

In FIGS. 11 and 12, the blade 1 is placed in a low temperature atmosphere R.
The case where cooling is performed and grinding is performed is shown. In the present embodiment, the surface 1a to be processed is embrittled by cooling the blade 1 itself. As a method of cooling the blade 1 itself, as shown in FIGS. 11A to 11B, a method of grinding the blade 1 in advance through a step of cooling the blade 1 in a low temperature atmosphere R, or as shown in FIG. A method of cooling the cutting tool 1 by heat conduction from the jig 5 in the low temperature state R'at the same time as the grinding process can be considered. According to this method, since the blade 1 itself is cooled, the reliability is further enhanced in embrittlement.

FIG. 13 shows an example of a case where the cutting tool 1 is frozen and is ground. In the present embodiment, as a method of freezing the object to be ground, a method of practically conceivably performing a grinding process through a step of freezing the blade 1 below freezing. In particular, if the cutting tool 1 is frozen in water, the circumference of the cutting tool 1 is formed of ice 4, and not only the low-temperature embrittlement action but also the surrounding ice functions as the jig 5, whereby the cutting edge at the time of grinding is cut. It can be expected to be a resistance against burr generation of 1b.

FIG. 14 shows an example of the case where the size of the blade at room temperature is predicted and the amount of processing under the low temperature atmosphere R is set to be larger than the amount of processing at room temperature. In the present embodiment, the amount of processing under the low temperature atmosphere R is set to a large amount in advance by predicting the dimension at room temperature. That is, the dimensional error due to the heat shrinkage caused by the temperature difference between the temperature during processing and the room temperature can be predicted in advance, and during freezing, only the predicted amount can be processed. Generally, if the linear expansion coefficient α of the material, the temperature difference ΔT, the reference dimension L of the target object, and the dimension change ΔL due to the temperature change, the relationship of ΔL / L = α · ΔT (corresponding to thermal strain) is obtained. To establish. Although thermal deformation does not occur in a similar manner for complex shapes, the tendency is that the deformation behavior can be qualitatively predicted from the above equation, and the dimensional change ΔL with respect to the temperature difference ΔT is ΔL.
= Α · L · ΔT, which is set as a predicted machining amount.
According to this method, the processing is performed according to the dimensions at room temperature, so that dimensional errors due to thermal expansion and contraction can be reduced as much as possible.

FIG. 15 shows a case where the surface to be processed 1a of the blade 1 which is in contact with the grindstone 2a is cooled to a low temperature atmosphere and grinding is performed. In the present embodiment, the surface to be processed 1a in contact with the grindstone 2a of the blade 1 is cooled to a low-temperature atmosphere so that the surface to be processed 1a is embrittled and grinding is performed, and the surface to be processed 1a is cooled. As a method, as shown in FIG. 15, a method of locally forcibly injecting the cooling medium 6a onto the work surface 1a with the cooling medium 6a from the nozzle 15 before or simultaneously with the grinding process can be considered. According to this method, since the cooling medium 6a is locally supplied, the device can be simplified easily. On the other hand, in the case of local cooling, it takes time to lower the temperature or temperature changes easily due to the heat capacity of the surroundings, so cooling must be performed continuously for a long time before grinding. .

16 and 17 show an example in which the grindstone 2a is cooled to a low temperature atmosphere and is ground.
In this embodiment, the grindstone 2a is cooled to be in a low-temperature atmosphere, and the grinding is performed without increasing the temperature of the surface 1a to be processed of the blade 1 that is in contact with the grindstone 2a. As a method of cooling the grindstone 2a, for example, as shown in FIG.
There is a method of forcibly injecting the cooling medium 6a onto the surface a by the nozzle 15, and in this case, the device is easy to simplify. As another method, as shown in FIG. 17, a cooling medium is enclosed around the rotating shaft 20 in the center of the grindstone 2a to cool the grindstone 2a.
A method of reducing the temperature in the directions indicated by arrows D and E toward the surface may be considered. According to the method of cooling the surface of the grindstone 2a shown in FIG. 16 or the method of transmitting cooling from the inside of the grindstone 2a shown in FIG. 17, since the temperature rise of the grindstone 2a is first suppressed, the damage of the grindstone 2a can be avoided.

FIG. 18 shows an example in which the entire blade 1 and the grindstone 2a are cooled to a low temperature atmosphere R and grinding is performed. In the present embodiment, grinding is performed by cooling the entire region constituted by the blade 1, the grindstone 2a, and the surface atmosphere to be processed in contact with the blade 1 and the grindstone 2a to a low temperature atmosphere R. As a cooling method, a method may be considered in which the blade 1 and the grindstone 2a are stored in a sealed space 9 such as a chamber and then the space 9 is cooled to the same low temperature atmosphere R. According to these methods, it is easy to control and maintain the blade 1, the grindstone 2a, and the work surface atmosphere at the same low temperature, and it is difficult for the temperature to change. Therefore, this method seems to be the most effective means when it is necessary to strictly control the processing temperature. As another method, for example, a means for cooling the cutting tool 1 shown in FIGS. 10 and 11 and a means for cooling the work surface atmosphere shown in FIG. 15 and the grindstone 2a shown in FIGS. It may be a method in which a means for cooling is combined.

FIGS. 19 and 20 show an example in which the gas 6 is used as the cooling medium. In this embodiment, the gas 6, which is used to cool the blade 1, the work surface atmosphere, the grindstone 2a, or the entire component to a low temperature atmosphere, is used. For example,
Cooling air, inert gases such as nitrogen are applied. As for the supply, if it is the atmosphere of the surface to be processed or the cooling of the grindstone 2a, for example
As shown in FIG. 9, a method of injecting the cooling gas to the target using the nozzle 15 can be considered. Further, as shown in FIG. 20, if the entire components are cooled, a method of enclosing a cooling gas in a sealed space 9 such as a chamber can be considered. According to these methods, it is easy to handle and supply, and an inert gas or the like has an effect of suppressing a work-affected layer caused by oxidation which is likely to occur during working.

21 and 22 show an example in which the liquid 7 is used as the cooling medium. In the present embodiment, the liquid 7 for cooling the blade 1, the surface atmosphere to be processed, the grindstone 2a, or the entire component to a low temperature atmosphere is used. For example, liquid nitrogen or liquefied carbon dioxide gas is applied. Supply is Figure 2
A method of ejecting the liquid 7 to the target using the nozzle 15 shown in FIG. Further, a method is conceivable in which the liquid 7 is sealed from the cooling source 21 shown in FIG. Further, in the case of cooling the grindstone 2a or the blade 1, a method of cooling the jig 5 by connecting a pipe to the inside of the jig 5 and flowing a liquid 7 can be considered. According to these methods, since the liquid 7 is handled, a large amount of equipment is required for supplying and leak-proofing a closed container, piping, etc., but in terms of cooling efficiency, the cooling efficiency is much higher than that of the gas 6, and processing is performed. It is possible to improve quality.

FIG. 23 shows a cooling medium 6 such as gas or liquid.
An example is shown in which a is circulated and repeatedly used. In the present embodiment, a cooling medium 6a for cooling the blade 1, the work surface atmosphere, the grindstone 2a or the entire component to a low temperature atmosphere is circulated and repeatedly used. The cooling medium 6a may be gas or liquid. Incidentally, as a method of injecting the cooling medium 6a using a nozzle or the like, a method of providing a duct in the rear and collecting and circulating is considered. Further, if the cooling of all the constituent elements is performed, as shown in FIG. 23, a supply port 23 and a discharge port 24 for the cooling medium 6a are provided in a sealed space 9 such as a chamber, and the cooling medium 6a from the cooling source 21 is removed. A method of circulating in the circulation path 25 can be considered. Further, in the case of cooling the grindstone 2a or the blade 1, the pipe may be connected to the inside of the grindstone 2a or the jig 5 of the blade 1 and the cooling medium 6a may be circulated from the outlet to the inlet while flowing the cooling medium 6a.
These methods are economical because the cooling medium 6a can be circulated and reused without waste. Further, in the case of a circulation system using a chamber or piping, the cooling medium 6a does not leak to the outside, and environmental problems are unlikely to occur.

Next, as another example of the method of embrittlement the work surface 1a of the blade 1 in a low temperature atmosphere, the material of the blade 1 is cooled as a body-centered cubic (bcc) type material to a low temperature atmosphere and ground. You may make it process. In this embodiment,
This is a method in which a body-centered cubic material is used as the material of the blade 1 and the blade 1 is embrittled in a low temperature atmosphere to perform grinding. As described above with reference to FIG. 10, it has been described that when the surface 1a to be processed of the cutting tool 1 is placed in a low temperature atmosphere, the ductility at room temperature is gradually reduced to suppress a work-affected layer such as a burr. Furthermore, by making the material have a body-centered cubic crystal structure, it changes to brittleness at a temperature where it has ductility at normal temperature, that is, to suppress the occurrence of burrs due to the effect of low temperature embrittlement. You can For example, mild steel (SM41B
The ratio of the brittle fracture surface in the impact test of (steel) and the temperature rapidly increase the ratio of brittleness in the range of + 10 ° C to -20 ° C. This abrupt change is a characteristic feature of body-centered cubic crystals, and an eigenvalue (ductile brittle transition temperature) that varies depending on the material.
have. Therefore, it is possible to process in a brittle state by controlling the temperature below the above temperature. According to this method, the effect of the material that is easily embrittled is overlapped with the effect of low temperature, and the effect in the embodiment of FIG.
High-quality machining such as heat-influence-free and extended life of the grindstone 2a can be expected.

As still another example, martensitic stainless steel may be used as the material of the cutting tool 1 and embrittlement processing may be performed in a low temperature atmosphere to perform grinding. In the present embodiment, martensite stainless steel is used as the material of the blade 1 in the embodiment in which the material of the blade 1 is a body centered cubic (bcc) type material and is cooled in a low temperature atmosphere to perform grinding processing. In this method, the cutting tool 1 is made to be in a low temperature atmosphere to be embrittled and then ground. Martensitic stainless steel is a body-centered cubic crystal, not only the effect shown in the above embodiment can be obtained, but also rust which is an original feature of stainless steel,
Due to its high resistance to corrosion, it is a convenient material for products such as the blade 1. Further, since the martensite system has magnetism, it can be fixed by magnetic attraction, which is convenient for fixing during processing. Table 1 shows the main chemical components Wt% of martensitic stainless steel. The martensitic stainless steel used in this method is a material that is convenient for products such as the blade 1 because it has high durability against rust and corrosion, and because it has magnetism, it can be fixed by magnetic attraction and fixed during processing. Is also convenient.

[0052]

[Table 1]

Next, in the case where the surface 1a to be processed of the cutting tool 1 is subjected to the embrittlement processing before or simultaneously with the grinding processing and the grinding processing is carried out, as shown in FIG. You may make it grind processing by supporting from a back surface side. When processing the cutting tool 1 such as the cutting tool 1, since the cutting edge 1b has a sharp shape, it is elastically deformed by a pressing force of the grindstone 2a, or is cracked or chipped. Further, burrs of the cutting edge 1b generated by plastic deformation grow on the free surface side. In order to avoid such inconvenience, as shown in FIG. 24, by providing a jig 5 capable of supporting the blade 1 from the back side, it is possible to prevent the blade 1 from being elastically deformed, cracked, chipped, and burr-grown. it can.

FIG. 25 shows an example of a case where the cutting edge 1b is supported from the back side by ice 4 for grinding during the processing. By supporting with ice 4, not only the effect shown in the embodiment of FIG. 24 can be obtained, but also the effect of cooling the blade 1 can be obtained, and the blade 4 can be supported by being covered with the ice 4 up to the vicinity of the blade tip 1b. If the ice 4 is cut at the same time as 1, the lateral growth of burrs that are likely to occur on the cutting edge 1b can be suppressed.

FIG. 26 shows an example of a case where the cutting edge 1b is supported by the wax 8 from the back surface side during the grinding for the grinding. By supporting with the wax 8, not only the effect shown in the embodiment of FIG. 24 can be obtained, but also a process in which the wax 8 is supported up to the vicinity of the cutting edge 1b so as to be supported and the wax 8 is scraped simultaneously with the blade 1. By doing so, it is possible to suppress lateral growth of burrs that are likely to occur on the cutting edge 1b. Further, the wax 8 can be easily fixed to the blade 1 and can be easily removed by heating even after the processing is completed.

FIG. 27 shows an example of a case where the cutting edge 1b is supported from the back side by a metal jig 5a during the grinding for the grinding. However, by supporting the cutting tool 1 from the back side by the metal jig 5a during processing, in addition to the effect shown in the embodiment of FIG. 24, the supporting rigidity with respect to the applied pressure is high, and the deformation suppression against elastic deformation and plastic deformation is suppressed. The effect can be enhanced.

28 and 29 show the work surface 1a of the blade 1.
An example of a case in which the jig is projected above the jig upper surface 5b in a stepped shape and grinding is performed so that the jig upper surface 5b becomes a finished surface. In this embodiment, as shown in FIG. 28, the cutting tool 1 is processed before the machining so that the jig upper surface 5b becomes a finishing surface.
On the other hand, a step D is provided on the jig upper surface 5b and the cutting edge 1b is set so as to be a free surface, and the grindstone 2a is cut to the jig upper surface 5b during processing. In this case, as shown in FIG. 29, the processed surface 1a on the free surface is brittlely fractured due to stress concentration due to the notch effect due to the step D with the jig 5, and removal processing can be performed at one time.
Further, it is possible to suppress the occurrence of burrs and sharpen the cutting edge 1b. Further, since the portion of the blade 1 covered with the jig 5 is supported by the jig 5, only the unnecessary portion can be removed without being affected by the destruction.

FIG. 30 shows hydrogen embrittlement as an example of material embrittlement. The present embodiment is a method in which the surface to be processed 1a of the cutting tool 1 is made brittle in a hydrogen atmosphere H to perform grinding. Generally, when a metal material is ground at room temperature in the atmosphere, it is plastically deformed according to the depth of cut. Therefore, the cutting edge 1b
In the case of sharpening, a work-affected layer such as burr is likely to occur. Therefore, as shown in FIG. 30, when the surface 1a to be processed is placed in the hydrogen atmosphere H, the property of being ductile in the air atmosphere is gradually reduced, that is, the property of hydrogen embrittlement is utilized to perform the processing. . By the way, in an atmosphere containing hydrogen, H penetrates into the work surface 1a to reduce Cu ₂ O and other oxides, and the generated steam causes cracks and vacancies at grain boundaries, which may cause brittleness. It is known and this is called hydrogen embrittlement. By applying this hydrogen embrittlement to the work surface 1a of the cutting tool 1 to be ground, it is possible to suppress the occurrence of burrs on the cutting edge 1b due to the reduction of plastic deformation and also reduce the energy during processing, thereby reducing the cutting resistance, The life of the grindstone 2a is also extended.

FIG. 31 shows an example of preliminarily embrittlement treatment by quenching as an example of material embrittlement in the case where grinding is performed after the embrittlement treatment. In this embodiment, as shown in FIGS. 31 (a) → (b) → (c), at least the surface 1a to be processed of the blade 1 is hardened to be embrittled by grinding and then ground. Generally, when a metal material is ground, it is plastically deformed according to the depth of cut. Therefore, when the cutting edge 1b is sharpened, a work-affected layer such as a burr is likely to occur. Therefore, by subjecting the work surface 1a to a quenching treatment in advance to harden the surface, the ductility of the surface layer 1c becomes brittle.
As a method, after heating to a predetermined temperature (in the case of steel: 700 ° C. to 900 ° C.) in a heating furnace J shown in FIG. 31A, it is rapidly cooled to room temperature at a predetermined cooling rate (in the case of steel: About 1
0 seconds or less). As a result, the surface layer 1c shown in FIG. 31 (b) has a higher cooling rate than the inside, and the surface layer 1c
Has the highest hardness, and surface embrittlement occurs. According to this method, it is possible to suppress the occurrence of burrs on the cutting edge 1b associated with the reduction of plastic deformation, and also reduce the energy during processing.
The cutting resistance is reduced during the machining shown in (c), and the life of the grindstone 2a is extended. Further, since only the surface layer 1c can be embrittled, the internal ductility can be maintained and the spread of damage such as chipping or chipping during processing can be suppressed.

FIG. 32 shows an example in which embrittlement treatment is carried out in advance by laser hardening. By the way, in quenching, a method of heating the entire blade 1 in a furnace and then quenching is generally used, but in this case, dimensional changes such as deformation are likely to occur due to temperature changes during heating or cooling and material structure transformation. . Therefore, only the periphery of the work surface 1a is irradiated with laser from the laser irradiation device 15a in advance to locally heat the surface, and then instantaneous cooling is performed. In the case of the blade 1, as shown in FIG.
Laser is irradiated only around the cutting edge 1b to heat it, and then it is rapidly cooled (state of FIG. 32 (b)). As a result, it is possible to heat-treat only a local portion (embrittlement area B) that requires embrittlement, and then perform the grinding process shown in FIG. 32 (c). Therefore, in addition to the effect of the embodiment of FIG. 31, the deterioration layer due to dimensional changes such as warpage and deformation and thermal influence can be reduced as much as possible.

FIG. 33 shows a case where nitriding embrittlement is performed as an example of material embrittlement, and embrittlement treatment is performed in advance by nitriding. In the present embodiment, at least the work surface 1a of the blade 1
Is a method of embrittlement by nitriding and performing grinding.
Generally, when a metal material is ground at room temperature, it is plastically deformed according to the depth of cut. Therefore, when the cutting edge 1b is sharpened, a work-affected layer such as a burr is likely to occur.
Therefore, in the case of targeting a metal material, the surface to be machined 1a is nitrided in advance to embrittle the surface of the blade 1 to suppress plastic deformation due to a pressing force during grinding. For example, as shown in FIG. 33 (a), the nitriding method is performed by storing the target material in the closed space 9 and then enclosing ammonia gas to raise the ambient temperature (500 ° C. to 600 ° C. in the case of steel). , Pressurization (7
kPa to 10 kPa) holds ammonia NH
₃ becomes unstable at high temperature, decomposes into N and H, and a nitriding atmosphere N is obtained. In the case of steel, decomposed N is combined with additional elements such as Fe or Al and Cr to disperse and form hard and brittle nitrides. According to this method, after nitriding embrittlement, as shown in FIG.
By subjecting the nitride layer 1d shown in (b) to grinding,
It is possible to suppress the occurrence of burrs on the cutting edge 1b due to the reduction of plastic deformation, reduce the energy during grinding, reduce the cutting resistance, and extend the life of the grindstone 2a. Further, since only the surface layer can be embrittled, the internal ductility can be maintained and the spread of damage such as chipping or chipping during grinding can be suppressed.

FIG. 34 shows a case where particle injection embrittlement is performed as an example of material embrittlement, and embrittlement treatment is performed in advance by particle injection. The present embodiment is a method in which particles are jetted onto at least the work surface 1a of the cutting tool 1 to make it brittle and to perform grinding. Generally, when a metal material is ground at room temperature, it is plastically deformed according to the depth of cut. Therefore, when the cutting edge 1b is sharpened, a work-affected layer such as a burr is likely to occur. Therefore, as shown in FIG. 34 (a), particles are sprayed in advance on the surface 1a to be locally deformed to locally deform the surface of the cutting tool 1 to cause work hardening and embrittlement at the same time, resulting in plasticity associated with a pressing force during grinding. Suppress deformation. The size of the injection method is μm
FIG. 34 is a plan view of an irregular or spherical metal or non-metal (ceramic, glass, resin, etc.) particle d of mm order.
It is accelerated by means such as the nozzle 15a shown in (a) and projected onto the surface of the blade 1. According to this method, innumerable dents are formed in the surface layer of the cutting tool 1 to cause work hardening and embrittlement, and at the same time, compressive residual stress can be applied to the surface layer. As a result, the embrittlement treatment can be performed only on the local portion (embrittlement area B) that requires embrittlement, and then the grinding process shown in FIG. 34C is performed. As a result, it is possible to suppress the occurrence of burrs on the cutting edge 1b due to the reduction of plastic deformation during grinding, and also to reduce the energy during grinding, thereby reducing the cutting resistance and increasing the grinding wheel 2.
The life of a is also extended. Further, since only the surface layer can be embrittled, the internal ductility can be maintained and the spread of damage such as chipping or chipping during grinding can be suppressed. Furthermore, the presence of compressive residual stress on the surface improves fatigue strength and extends the life of the product.

35 and 36 show application of a brittle film as an example of material embrittlement. In this embodiment, a method is shown in which a different material is added in a film shape to at least the surface 1a to be processed of the blade 1 to make it brittle and to perform grinding. Generally, when a metal material is ground at room temperature, it is plastically deformed according to the depth of cut. Therefore, when the cutting edge 1b is sharpened, a work-affected layer such as a burr is likely to occur. Therefore, in the space 9 such as the chamber, the work surface 1a is previously prepared.
Further, a different material is added in a film form to harden the surface of the blade 1 and at the same time embrittle it, thereby suppressing the plastic deformation associated with the pressing force during processing. Examples of different materials include DLC (diamond-like carbon), titanium alloys, ceramics, and the like. Sputter deposition, or physical attachment processing such as ion plating for releasing a deposition substance e from the ion source 50 shown in FIG. By the method, a pure film can be formed on the surface. According to this method, since the surface layer 1e of the cutting tool 1 is made of a brittle material, it is possible to suppress the occurrence of burrs on the cutting edge 1b due to the reduction of plastic deformation during the processing shown in FIG. Further, the energy during processing can be reduced, the cutting resistance is reduced, and the life of the grindstone 2a is extended. Further, since only the surface layer 1e can be embrittled, internal ductility can be maintained,
It is possible to suppress the spread of damage such as chipping and chipping during processing. Furthermore, the presence of compressive residual stress on the surface improves fatigue strength and extends the life of the product.

FIG. 37 shows an example of a processing apparatus for carrying out each of the above processing methods. In the present embodiment, a closed space 9 for storing the tool 1, a means for embrittlement the tool 1, and a processing tool 2 for grinding the embrittled tool 1 by making the space 9 a brittle atmosphere. Is provided, and the cutting tool 1 is embrittled for grinding. The space 9 is preferably a pressure resistant object such as a so-called chamber that is made of a rigid body so that the atmosphere inside can be maintained. Space 9
As a means for introducing an embrittlement atmosphere into the inside, for example, as shown in FIG. 37, when a low temperature embrittlement atmosphere is used, the cooling source 21 and the space 9 are connected by a pipe 60, and the cooling source 21 and the space 9 are connected. It is arranged so that the cooling medium 6a can be introduced therein.
The processing tool 2 includes a grindstone 2a for grinding the blade 1, a grindstone driving device (not shown) for rotating the grindstone 2a, a stage 16 for fixing the blade 1, and the stage 16 for the grindstone 2a. It is composed of a stage drive device 17 for relatively moving, and these are all stored inside the space 9. With the above configuration, it becomes possible to perform grinding processing in a brittle atmosphere in real time. The procedure is shown in the flowchart of FIG. FIG. 39 shows an example in which an embrittlement atmosphere is created by the cooling medium 6a before the grinding step, and FIG. 40 shows the subsequent grinding step. This grinding process is performed in the same procedure as the flowchart of FIG. According to this method, a large number of blades 1 can be stored in the closed space 9 for mass production in batch. Further, by using this device, it is possible to suppress the occurrence of burrs during grinding, and it is possible to reduce the deburring process that has been performed so far.

41 to 44 illustrate an inner blade 12 of a reciprocating electric shaver as an example of the blade 1. As shown in FIG. 44, the inner blade 12 of the present example includes an outer blade 11 having a blade hole, and an inner blade 12 that slides on the inner surface of the outer blade 11 and reciprocates in the direction indicated by arrow C. Here, at least the inner blade 12 that is a sliding contact portion with the outer blade 11 is embrittled, and the inner blade 12 is ground by the processing tool 2.
For example, as shown in FIG. 41, the manufacturing process of the inner blade 12 is as follows. After the inner blade piece 12a obtained by punching a metal plate 10 such as stainless steel into a substantially semicircular shape by press working in the space 9,
The inner blade 12 is integrated with a synthetic resin by injection molding, and then the integrated inner blade 12 is ground with a grindstone 2a having a cross-sectional shape to finish it to a desired size and form an edge on the inner blade edge 12b. There is a way to do it.
As another manufacturing process, as shown in FIG. 42, a plurality of bars 12c are formed by punching a metal plate 10 such as stainless steel into a slit shape by press working, and heat-treating the bars 12c in a space 9. , The surface is finished to a desired size by surface grinding with the grindstone 2a, and an edge is formed on the inner blade edge 12b. Further, there is a method in which the remaining portion is bent in the direction indicated by the arrow B to be formed into a substantially semicircular shape (a semi-cylindrical shape), and then is integrated with the base portion 13 by injection molding together with a synthetic resin.
Conventionally, in any case, a burr 10 is produced at the edge portion of the cutting edge 1b during grinding as shown in FIG. 43 (b).
The presence of the burr 10 makes the sharpness of the cutting edge 1b dull, which causes the shaver taste of the electric razor to be impaired. Therefore, it is the actual state that the burr 10 is removed and finished by rotating brush, sand blasting, electrolytic polishing, magnetic polishing or the like after grinding. On the other hand, according to the method of the present invention, the inner blade 12 is embrittled in advance or in real time at the time of machining as described above, and then the grinding process is performed. Therefore, the semi-disc type shown in FIG. Figure 4
In any of the thin-walled annular type shown in FIG. 2, the blade edge cross section has a flat inner blade edge 12 on one side as shown in FIG. 43 (a).
b, a cutting edge 1b having an acute angle is formed at one corner, and a rib 3 having a convex cross-section is provided on the back side. This allows
It is possible to obtain a high-quality inner blade 12 with no burrs on the cutting edge 1b during grinding, and to eliminate the burring removal step that has been required so far, so that it is possible to provide a low-cost inner blade 12.

The method and apparatus for processing a blade of the present invention may be a hair cutter, an electric hair clipper blade, etc., in addition to the inner blade for a reciprocating electric razor, and is widely applicable to various general blades. .

[0067]

As described above, in the method of processing a cutting tool according to the first aspect of the present invention, in cutting the cutting edge of the cutting tool,
At least the surface to be machined of the blade is embrittled before or at the same time as the grinding process, so that the grinding process is performed, so that the embrittlement of the blade minimizes the work-affected layer such as plastic deformation during machining. Thus, it becomes possible to suppress the occurrence of burr on the cutting edge due to plastic deformation. This eliminates the need for deburring work in the subsequent process. Further, suppressing the plastic deformation on the surface to be processed is that the energy consumed for the plastic deformation can be reduced, and the cutting resistance for the processing tool decreases, so that the effect of suppressing the burr of the cutting edge due to embrittlement can be obtained. In addition, it is possible to reduce power consumption during processing and extend the life of the processing tool.

In addition to the effect of claim 1, the invention of claim 2 has one side of the blade as a surface to be processed and a rib having a convex cross section on the back side, so that both sides can be used like a safety razor. Even without grinding, it is possible to sharpen the cutting edge only by one-side grinding. In addition, by providing convex ribs, it is possible to obtain a sensual effect of resonance-amplifying the sound of beard shaving and giving a feeling of shaving.

According to the invention of claim 3, in addition to the effect of claim 2, since the blade is subjected to embrittlement treatment in real time to perform grinding processing, an embrittlement atmosphere is created in the blade in real time, and during processing. Since the atmosphere state is always maintained, the atmosphere variation due to the processing is suppressed, brittle processing during the processing can be surely performed, and the processing quality can be improved.

According to the invention of claim 4, in addition to the effect of claim 2, since the blade is subjected to embrittlement treatment in advance and grinding is performed, the embrittlement treatment and the grinding can be performed separately. Further, by setting the desired material properties in advance, the processing apparatus can be simplified and the manufacturing cost can be reduced.

According to the invention of claim 5, in addition to the effect of claim 3 or 4, since the blade is subjected to embrittlement treatment in a low temperature atmosphere to perform grinding, a metal material is generally ground at room temperature. In this case, plastic deformation is associated with the depth of cut, and in the case of sharpening the cutting edge, a work-affected layer such as burrs is likely to occur, but by making the cutting tool a low-temperature atmosphere, it is ductile at room temperature. It is possible to perform processing by utilizing the property that the above property gradually decreases. In other words, the rate of brittleness increases as the temperature decreases, and it is possible to suppress the occurrence of burrs on the cutting edge due to plastic deformation reduction, and also reduce the energy during processing, reducing cutting resistance and extending the tool life. . Further, since the temperature is low, thermal influences such as thermal deformation and seizure can be suppressed as much as possible, and the working tool life can be further extended.

In addition to the effect of claim 5, the invention of claim 6 cools the blade in a low temperature atmosphere to perform grinding, so that the surface to be processed is embrittled by cooling the blade itself. It can be in a state, and processing reliability can be improved.

According to the invention of claim 7, in addition to the effect of claim 6, since the blade is frozen for grinding, the freezing of the blade causes not only a low temperature embrittlement action but also surrounding ice. It plays the role of a jig and can suppress burrs on the cutting edge.

In addition to the effect of claim 5 or 6 or 7, the invention according to claim 8 predicts the size of the blade at room temperature to process the amount of processing under a low temperature atmosphere at room temperature. Since the amount is set larger than the amount, the dimensional error due to thermal expansion and contraction can be reduced as much as possible, and the finished dimensional accuracy at room temperature can be improved.

Further, in addition to the effect of claim 5, the invention of claim 9 cools a surface to be processed in contact with a tool of a blade to a low temperature atmosphere to perform grinding, so that, for example, a cooling medium such as a nozzle is used. It is possible to locally cool the work surface in contact with the machining tool of the blade simply by spraying the work surface onto the work surface.This simplifies the device and ensures that the work surface is embrittled. Grinding can be performed.

In addition to the effect of the fifth aspect, the invention of claim 10 increases the temperature of the surface to be machined of the blade which is in contact with the machining tool, because the machining tool is cooled to a low temperature atmosphere for grinding. Since the embrittlement treatment can be performed without causing it and the temperature rise of the processing tool can be suppressed, damage due to heat can be avoided.

According to the invention of claim 11, in addition to the effect of claim 5, grinding is carried out by cooling the blade and the working tool as a whole to a low temperature atmosphere. Since the control can be easily maintained and the temperature change due to the processing hardly occurs, the temperature can be easily controlled even when the processing temperature needs to be strictly controlled.

In addition to the effect of the sixth aspect, the ninth aspect, the tenth aspect, or the eleventh aspect of the invention, since a gas is used as the cooling medium, the cooling medium can be easily handled and supplied. In particular, a gas such as an inert gas has an effect of suppressing a work-affected layer caused by oxidation that is likely to occur during working.

In addition to the effect of the sixth aspect, the ninth aspect, the tenth aspect, or the eleventh aspect, since the liquid is used as the cooling medium, the cooling efficiency is much higher than that of the gas. It is possible to improve processing quality.

In addition to the effect of the sixth aspect, the ninth aspect, the tenth aspect, or the eleventh aspect of the invention, since the cooling medium is circulated and repeatedly used, the cooling medium can be circulated and reused without waste, which is economical. In particular, in the case of a circulation system using a chamber or piping, the cooling medium does not leak to the outside and environmental problems are less likely to occur.

According to a fifteenth aspect of the present invention, in addition to the effect of the fifth aspect, since the blade is made of a body-centered cubic crystal material, when the blade is cooled to a low temperature atmosphere to perform grinding, Since the cubic material has a characteristic that the ratio of brittleness increases rapidly at a predetermined temperature, rapid brittleness is easily caused by the effect of low temperature embrittlement, which can suppress the occurrence of burrs and The effect of extending the tool life is further enhanced.

In addition to the effect of claim 5, since the blade is made of martensitic stainless steel, when the blade is cooled to a low temperature atmosphere and is ground, the martensitic stainless steel is used. Since stainless steel has high durability against rust and corrosion, it is suitable as a material for the blade, and since it has magnetism, it can be fixed by magnetic attraction, which is also convenient during processing.

Further, in addition to the effect of claim 3 or 4, the invention of claim 17 carries out grinding by supporting the blade from the back side with a jig at the time of processing, so that a sharp edge is used. By supporting from the back surface side, it is possible to prevent elastic deformation, cracking or chipping due to the pressing force of the working tool, and also to prevent burr growth.

The invention according to claim 18 is the invention according to claim 17
In addition to the effects described, since the jig is ice, the cutting edge can be cooled by ice to promote embrittlement by supporting the cutting edge from the back side with ice during processing and performing grinding. By performing processing such that the vicinity is covered with ice to support and the ice is cut at the same time as the blade, it is possible to suppress lateral growth of burrs that are likely to occur at the blade edge.

The invention according to claim 19 is the method according to claim 17
In addition to the effects described, since the jig is wax,
When performing grinding by supporting the cutting edge from the back side with wax during processing, if the cutting is done at the same time as the blade by supporting it so that it covers the area near the cutting edge as well as cutting the wax at the same time Lateral growth can be suppressed. Further, the wax can be easily fixed to the blade and can be easily removed by heating even after the processing is completed.

The invention of claim 20 is the same as that of claim 17
In addition to the effects described, since the jig is metal, by supporting the blade edge from the back side with a jig made of metal at the time of processing to perform grinding, the supporting rigidity with respect to the pressing force is high,
It is possible to enhance the effect of suppressing deformation against elastic deformation and plastic deformation.

The invention according to claim 21 is the invention according to claim 17.
In addition to the effects described above, it is preferable that the surface to be processed of the blade is projected in a step shape above the upper surface of the jig, and the grinding is performed so that the upper surface of the jig is the finished surface. The work surface projecting upward is brittle fracture due to stress concentration due to the notch effect due to the step with the jig, and it becomes possible to remove it at one time, and the blade 1 part supported by the jig is affected by the fracture. Only the unnecessary part can be removed without receiving.

In addition to the effect of claim 3 or 4, the invention according to claim 22 performs the embrittlement treatment of the blade in a hydrogen atmosphere and performs the grinding process. It is possible to perform processing by utilizing the property of hydrogen embrittlement, which is a property of ductility in an atmosphere, which gradually decreases. Therefore, it is possible to suppress the occurrence of burrs on the cutting edge due to the reduction of plastic deformation and also reduce the energy at the time of working, and further, reduce the cutting resistance and extend the life of the working tool. Further, at least the surface to be processed can be embrittled only by irradiating it with hydrogen, and the apparatus can be simplified.

According to the invention of claim 23, in addition to the effect of claim 4, since the blade is subjected to embrittlement treatment by quenching, the blade is preliminarily subjected to quenching treatment to harden the surface in advance, so that it is ductile. As a result, the surface layer has brittleness, so that the surface layer has a higher cooling rate than the inside, and the hardness of the surface layer is most increased to cause surface embrittlement. Therefore, it is possible to suppress the occurrence of burrs on the cutting edge due to the reduction of plastic deformation, reduce the energy during processing, reduce the cutting resistance and extend the life of the processing tool, and additionally, it is possible to embrittle only the surface layer. Therefore, the internal ductility can be maintained,
It is possible to suppress the spread of damage such as chipping and chipping during processing.

The invention according to claim 24 is the same as claim 23.
In addition to the effects described, the blade is subjected to embrittlement treatment by laser hardening, so by pre-irradiating the periphery of the surface of the blade with a laser to locally heat it, heat treatment can be performed only on the local area requiring embrittlement. In addition, since the region in which quenching is performed can be limited, the deterioration layer due to dimensional changes such as warpage and deformation and thermal influence can be reduced as much as possible.

According to the invention of claim 25, in addition to the effect of claim 4, since the cutting tool is embrittled by nitriding, the surface of the cutting tool is embrittled by nitriding in advance so that the pressing force is applied during processing. Plastic deformation can be suppressed, and the spread of damage such as chipping and chipping can be suppressed.

In addition to the effect of claim 4, in the invention of claim 26, since the blade is embrittled by particle spraying, the particle surface is locally sprayed beforehand by spraying particles on the surface of the blade. It is possible to suppress the plastic deformation that accompanies the pressurizing force during processing by deforming and embrittlement simultaneously with work hardening. Further, the presence of compressive residual stress on the surface improves fatigue strength and prolongs the life of the product.

According to the invention of claim 27, in addition to the effect of claim 4, since the embrittlement treatment is performed by adding a different material to the surface of the blade in a film form, the surface layer of the blade is made of a brittle material. Therefore, during processing, it is possible to suppress the occurrence of burrs on the cutting edge due to the reduction of plastic deformation. Furthermore, the energy required for machining can be reduced, cutting resistance is reduced, and the machining tool life is extended. Furthermore, since only the surface layer can be embrittled, the internal ductility can be maintained, the spread of damage such as chipping and chipping during processing can be suppressed, and the presence of compressive residual stress on the surface results in fatigue strength. Improves the product life and prolongs its life.

According to a twenty-eighth aspect of the present invention, there is provided an apparatus for processing a blade, wherein at least a means for making the surface to be processed of the blade brittle, a space for creating a brittle atmosphere around the blade, and a brittle blade are provided. Since it is possible to perform grinding by embedding at least the work surface of the blade by using a processing tool for grinding, it is possible to perform grinding while making the periphery of the tool brittle in real time. It will be possible.
Also, by storing multiple blades in the space, mass production in batch is possible, and by making the surface of the blades to be embrittled and performing grinding, it is possible to suppress the occurrence of burrs during grinding and A processing device capable of reducing the number of steps can be provided.

According to a twenty-ninth aspect of the present invention, in the inner blade for an electric shaver, the blade is an inner blade which is in sliding contact with the inner surface of the outer blade having a blade hole, and is at least a sliding contact portion with the outer blade. Since the cutting edge is embrittled and subjected to grinding processing, there is no burr on the cutting edge during grinding, the sharpness of the cutting edge is improved and a high quality inner blade with good shaving taste is obtained. At the same time, the burr removing step which has been necessary up to now becomes unnecessary, and a low-cost inner blade can be provided.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of an embodiment of the present invention.

FIG. 2A is a perspective view of a semi-disc type inner blade, and FIG.
FIG. 4 is a perspective view of an inner blade piece.

FIG. 3A is a perspective view of a thin-walled annular type inner blade,
(B) is a perspective view of an inner blade piece.

FIG. 4 is a sectional view taken along line AA of FIG. 2B and a sectional view taken along line A′-A ′ of FIG.

FIG. 5 is a flowchart at the time of the grinding process of the same.

FIG. 6 is a schematic view of another example.

FIG. 7 is a schematic view of still another example.

FIG. 8 is a flowchart of the above-mentioned embrittlement processing and grinding processing.

FIG. 9A is a schematic view of another embrittlement process, and FIG. 9B is a schematic view of a grinding process.

FIG. 10 is a schematic view of still another example.

11A and 11B are schematic views of still another example.

FIG. 12 is a schematic view of still another example.

FIG. 13 is a schematic view of still another example.

14A and 14B are schematic diagrams of still another example.

FIG. 15 is a schematic view of still another example.

FIG. 16 is a schematic view of still another example.

17 (a) and 17 (b) are schematic views of still another example.

FIG. 18 is a schematic view of still another example.

FIG. 19 is a schematic view of still another example.

FIG. 20 is a schematic view of still another example.

FIG. 21 is a schematic view of still another example.

FIG. 22 is a schematic view of still another example.

FIG. 23 is a schematic view of still another example.

FIG. 24 is a schematic view of still another example.

FIG. 25 is a schematic view of still another example.

FIG. 26 is a schematic view of still another example.

FIG. 27 is a schematic view of still another example.

FIG. 28 is a schematic view of still another example.

FIG. 29 is a schematic view of still another example.

FIG. 30 is a schematic view of still another example.

31A to 31C are schematic views of still another example.

32A to 32C are schematic views of still another example.

33A to 33C are schematic views of still another example.

34A to 34C are schematic views of still another example.

FIG. 35 is a schematic view of still another example.

FIG. 36 is a schematic view of still another example.

FIG. 37 is a schematic view of the above processing apparatus.

FIG. 38 is a flowchart of the above.

FIG. 39 is a schematic view of still another example.

FIG. 40 is a schematic view of still another example.

FIG. 41 is an explanatory diagram of a manufacturing process of a semi-disc type inner blade.

FIG. 42 is an explanatory diagram of a manufacturing process of a thin-walled annular type inner blade.

FIG. 43 (a) is a cross-sectional view of the same cutting edge, and FIG. 43 (b) is an explanatory view of a cutting edge burr.

FIG. 44 is an exploded perspective view of an outer blade and an inner blade of the electric shaver.

[Explanation of symbols]

1 cutlery 1a Work surface 1b cutting edge 2 processing tools 3 ribs 4 ice 6 gas 7 liquid 8 wax 9 space 10 jigs 11 outer blade 12 inner blade 12b inner edge

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Claims (29)

[Claims] 1. A method for processing a blade, wherein in the cutting edge processing of the blade, at least a surface to be processed of the blade is embrittled before or at the same time as the embrittlement, and then the grinding is performed. 2. The method for processing a blade according to claim 1, wherein one side of the blade is a surface to be processed and a rib having a convex cross section is provided on the back side. 3. The method for processing a cutting tool according to claim 2, wherein the cutting tool is embrittled in real time and then ground. 4. The method for processing a cutting tool according to claim 2, wherein the cutting tool is embrittled in advance and then ground. 5. The method for processing a cutting tool according to claim 3, wherein the cutting tool is embrittled in a low temperature atmosphere and then ground. 6. The method for processing a blade according to claim 5, wherein the blade is cooled to a low temperature atmosphere and then ground. 7. The method of processing a blade according to claim 6, wherein the blade is frozen and then ground. 8. The blade according to claim 5, 6 or 7, wherein the dimension of the blade at room temperature is predicted and the amount of processing in a low temperature atmosphere is set to be larger than the amount of processing at room temperature. Processing method. 9. The method for processing a blade according to claim 5, wherein the surface to be processed in contact with the tool for processing the blade is cooled to a low temperature atmosphere to perform grinding. 10. The method for machining a blade according to claim 5, wherein the machining tool is cooled to a low temperature atmosphere and then ground. 11. The method for processing a blade according to claim 5, wherein the entire blade and the processing tool are cooled to a low temperature atmosphere and then ground. 12. The method of processing a blade according to claim 6, wherein a gas is used as the cooling medium. 13. The method of processing a blade according to claim 6, wherein a liquid is used as the cooling medium. 14. The method for machining a blade according to claim 6, wherein the cooling medium is circulated and repeatedly used. 15. The method for processing a blade according to claim 5, wherein the blade is made of a body-centered cubic crystal material. 16. The method for processing a blade according to claim 5, wherein the blade is made of martensitic stainless steel. 17. The method of processing a blade according to claim 3, wherein the blade is supported from the back side by a jig during the processing to perform grinding. 18. The method according to claim 17, wherein the jig is ice. 19. The method of processing a blade according to claim 17, wherein the jig is wax. 20. The method according to claim 17, wherein the jig is made of metal. 21. The grinding work is performed by projecting the surface of the blade to be processed in a step shape above the jig upper surface so that the jig upper surface becomes a finished surface. Alternatively, the method for processing a blade according to 19 or 20. 22. The method for processing a cutting tool according to claim 3, wherein the cutting tool is embrittled in a hydrogen atmosphere and ground. 23. The method for processing a cutting tool according to claim 4, wherein the cutting tool is embrittled by quenching. 24. The method for processing a cutting tool according to claim 23, wherein the cutting tool is embrittled by laser hardening. 25. The method for processing a cutting tool according to claim 4, wherein the cutting tool is embrittled by nitriding. 26. The method for processing a cutting tool according to claim 4, wherein the cutting tool is embrittled by particle injection. 27. The method for processing a blade according to claim 4, wherein the embrittlement treatment is performed by adding a different material to the surface of the blade in a film form. 28. At least means for embrittlement the surface to be processed of the blade, and a space for making the periphery of the blade an embrittlement atmosphere.
A processing device for a blade, comprising: a processing tool for grinding an embrittled blade, and at least enabling the surface to be processed of the blade to be embrittled for grinding. 29. The blade is an inner blade that is in sliding contact with the inner surface of an outer blade having a blade hole, and at least the inner blade edge that is the sliding contact portion with the outer blade is embrittled and ground. Inner blade for electric razor characterized by.